I'm still not entirely sure what it exactly is that you are trying to do.
If the plugin attached above is correct (link to mod please?), then it means it had no submenu to start with, and only a MVAM menu?
And it is exactly the same method, as SubMenu = '####', except that it expects a 0 or a 1 and not text.
You must know that those values at the top are not magical names, they are added to the ship on the ShipDef line, the same place where you would have to add the bMvamMenu in the same way as SubMenu and SubSubMenu.